NetEase Music cache uc! → mp3

neteasemusic.rs

// rustc neteasemusic.rs -O

use std::io::{Read, Write};

fn main() {
  let args = std::env::args().collect::<Vec<_>>();
  if args.len() == 1 {
    println!("Usage: {} <uc file> [<uc file> ...]", args[0]);
    return;
  }

  for in_path in args.iter().skip(1) {
    let out_path = in_path
      .trim_end_matches(".uc!").trim_end_matches(".mp3").to_string()
      + ".mp3";

    println!("In  {}", in_path);
    println!("Out {}", out_path);
    let mut in_file = match std::fs::OpenOptions::new()
        .read(true).open(&in_path) {
      Ok(f) => f,
      Err(e) => { println!("Err opening input: {}", e); continue; },
    };
    let mut out_file = match std::fs::OpenOptions::new()
        .write(true).create_new(true).open(&out_path) {
      Ok(f) => f,
      Err(e) => {
        if e.kind() == std::io::ErrorKind::AlreadyExists {
          print!("    Already exists, replace? (y/N) ");
          let mut s = String::new();
          let _ = std::io::stdout().flush();
          match std::io::stdin().read_line(&mut s) {
            Ok(_) => if s.trim().to_ascii_lowercase() != "y" {
              println!("    Skipping");
              continue;
            },
            _ => { println!("    Skipping"); continue; },
          };
          match std::fs::OpenOptions::new()
              .write(true).create(true).truncate(true).open(&out_path) {
            Ok(f) => f,
            Err(e) => { println!("Err opening output: {}", e); continue; },
          }
        } else {
          println!("Err opening output: {}", e);
          continue;
        }
      },
    };

    const BUF_SIZE: usize = 1024;
    let mut buf = [0u8; BUF_SIZE];
    loop {
      let n = match in_file.read(&mut buf) {
        Ok(0) => break,
        Ok(n) => n,
        Err(e) => { println!("Err reading input: {}", e); break; },
      };
      for p in buf.iter_mut().take(n) { *p ^= 0xa3; }
      if let Err(e) = out_file.write_all(&buf) {
        println!("Err writing output: {}", e);
        break;
      }
    }
  }
}